| 摘要: |
| 采用微孔板培养法,研究了爪哇曲壳藻亚缢变种胞外多聚物的分泌过程及除草剂对该过程的影响。结果表明,爪哇曲壳藻亚缢变种胞外多聚物的分泌过程分为4期即单细胞形成及重新定位期、球状体形成期、领形成和柄延伸期及细胞分裂增殖期。除草剂对胞外多聚物分泌的影响与其浓度有关当除草剂浓度为10×10-6时,除草剂对爪哇曲壳藻亚缢变种单细胞的形成和运动没有影响,但胞外多聚物柄的生产受到抑制,柄的长度也明显缩短;随着除草剂浓度的进一步增加,群体细胞不能散开形成单细胞,胞外多聚物的分泌受到完全抑制。本研究结果表明,爪哇曲壳藻亚缢变种胞外多聚物的分泌与细胞运动有关,除草剂可能影响了细胞内有机物质的合成和某些细胞器(如囊泡)的功能,从而抑制了胞外多聚物的分泌。 |
| 关键词: 爪哇曲壳藻亚缢变种 胞外多聚物 分泌过程 除草剂 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目,39900020号 |
附件 |
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| SECRETION PROCESS OF EXTRACELLULAR POLYMERS IN ACHNANTHES JAVANICA VAR. MEISTER AND THE IMPACT BY HERBICIDE |
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HUANG Shi-Yu1, WANG Da-Zhi2
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1.Fisheries College, Jimei University, Xiamen, 361021;2.State Key Lab of Marine Environmental Science/Environmental Science Research Center, Xiamen University, Xiamen, 361005
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| Abstract: |
| Achnanthes spp. is a prominent member of fouling communities in marine environments, which produces long extracellular polymeric substances (EPSs)-stalks and attaches to the surfaces of various substrates. This study investigated the secretion process by Achnanthes javanica var. Meister isolated from coastal waters of Xiamen, using micro-plate culture method, and the impacts of three herbicides on the secretion process were also investigated. The results showed that the secretion process could be divided into four phases. The first phase is single cell formation and cell reorientation phase, which started after 4–5h of inoculation of cells. Single cell separated from a filamentous colony and moved till a suitable position was found. The second phase is spherical pad formation; the cell motility stopped 2 to 3 h after the cell attached to the bottom. A small globular structure (pad) was produced in one side of the cell surface. The third phase is stalk elongation and collar-shaped structure formation, a highly structured stalk was formed and elongated 10 to 12h after the inoculation. Meanwhile, a collar structure also formed near the valve. The last phase is cell division and multiplication. Cells were multiplied successively and formed a filamentous colony or a stack of cells 12h after the inoculation.
The impacts of herbicides on the secretion process depend on herbicide’s concentrations. At 10×10-6, the formation of single cell was not affected and majority of cells could move, but the secretion was constrained and the length of the stalk was shortened significantly. 60% of the cells produced extracellular polymers and about 12% of them were with long stalks. Cell division was constrained in some cells. At concentration of 30×10-6, formation of single cell kept going but motility was inhibited inmost cells, and the secretion of globular structure (pad) was inhibited in 60% of total cells. Stalks formation and cell division were completely stopped. At higher herbicide concentration of 80×10-6, formation of single cell was ceased and some cells were dead. The results demonstrate that the secretion of EPSs is a fast and essential biological process in A. javanica var. Meister, which depends on cell motility. Some organelles such as vesicles in cytoplasm may involve in EPS biosynthesis. The herbicides inhibit single cell formation and cell motility, influence organelle synthesis and their functions, which results in inhibition of EPS secretion. |
| Key words: Achnanthes javanica var. Meister, Extracellular polymeric substances (EPSs), Secretion process, Herbicide |
